From 1966 through 1975, 73 patients aged 60 years and over and 277 patients under 60 underwent isolated aortic valve replacement (AVR) for aortic stenosis (AS), regurgitation (AR) and mixed disease (AS/AR). Cardiac catheterization was performed 5-9 months following operation in 77 percent of these patients. Followup averaged 55 months per patient.